Artificial Long Estrus Protocols Administered Prior to Progesterone Increase Endometrial Uterocalin Expression in Anestrous Mares.
Abstract: Uterocalin (P19) is a lipocalin protein that has binding activity for the provisioning of the embryo with lipids, including those essential for morphogenesis and pattern formation. Therefore, it is thought that P19 plays an important role in supporting the survival of the early embryo. Previous research has shown that the endometrium from acyclic mares expressed more P19 following a simulated long estrus: treatment of 8 mg of estradiol benzoate (EB) split over five consecutive days, followed by long-acting progesterone administration (LA-P4) 72 hours later, when compared to a single 2.5 mg EB treatment. The main objective of this study was to evaluate if a new long estrus protocol, with fewer EB administrations, also increases endometrial uterocalin expression. Fifteen mares were assigned to three groups: long estrus 5 administrations (LE5; a total of 8 mg of EB in increasing doses was given over five consecutive days, Day -7 to Day -3); long estrus 2 administrations (LE2; 3 and 5 mg EB were given on Day -7 and Day -4); and short estrus (SE; a single dose of 2.5 mg EB was administered on Day -2). All groups received LA P4 on day 0 (D0). Daily ultrasonography and blood collections were performed to assess uterine edema and estradiol and progesterone plasma concentrations, respectively. Endometrial biopsies were collected on Day 4 to evaluate P19 expression by RT-qPCR. There were no differences in P19 expression between groups LE2 and LE5. However, P19 expression was higher (P .1). In conclusion, the two EB administrations protocol is more feasible for preparing acyclic recipient mares at field conditions. However, a positive effect of the LE protocols on embryo survival and viability in anestrous treated mares still needs to be confirmed.
Copyright © 2021 Elsevier Inc. All rights reserved.
Publication Date: 2021-06-06 PubMed ID: 34281646DOI: 10.1016/j.jevs.2021.103669Google Scholar: Lookup
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- Journal Article
Summary
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The research article investigates if a simplified procedure for stimulating long estrus in acyclic mares can efficiently increase a protein expression (Uterocalin) responsible for early embryo survival. The experiment results suggest that fewer Estradiol Benzoate (EB) administrations in the revised protocol are as effective as the regular lengthy procedure.
Objectives and Methodology
- The main aim of the study was to determine if a revised long estrus protocol that uses fewer EB administrations can still enhance Uterocalin expression in acyclic mares’ endometrium.
- The researchers used 15 mares divided into three groups, each group undergoing a different treatment involving varied numbers of EB administration days and varying EB dosage.
- Health parameters such as uterine edema, and plasma concentrations of estradiol and progesterone, were monitored regularly via daily ultrasonography and blood sample testing.
- Endometrial biopsies were conducted on the fourth day to measure Uterocalin expression.
Findings
- The study observed no difference in Uterocalin expression between the group that received five EB administrations and the one that received only two.
- However, both the groups that underwent long estrus protocols had significantly higher Uterocalin expression than the group that underwent the short estrus method.
- Additionally, both long estrus protocol groups exhibited high uterine edema for a protracted period of 6 days.
- The research found no impact of the number of EB administrations (two or five) on overall estradiol and progesterone concentrations.
Conclusion
- The research concludes that a two EB administration protocol is a more practical approach when preparing acyclic recipient mares in field conditions.
- The authors mention a need for additional studies to confirm the effects of these two extended estrus protocols on the embryo survival and viability in anestrous treated mares.
Cite This Article
APA
Silva ESM, Vaz IS, Rodrigues TS, Brandão FZ, Oquendo PS, Oquendo FMG, Beletti ME, Cuervo-Arango J.
(2021).
Artificial Long Estrus Protocols Administered Prior to Progesterone Increase Endometrial Uterocalin Expression in Anestrous Mares.
J Equine Vet Sci, 103, 103669.
https://doi.org/10.1016/j.jevs.2021.103669 Publication
Researcher Affiliations
- School of Veterinary Medicine, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil. Electronic address: elisasmsilva@ufu.br.
- School of Veterinary Medicine, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil.
- School of Veterinary Medicine, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil.
- School of Veterinary Medicine, Fluminense Federal University, Rio de Janeiro, Rio de Janeiro State, Brazil.
- School of Veterinary Medicine, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil; Gallop Equine Veterinary Medicine, Uberlândia, Minas Gerais, Brazil.
- Gallop Equine Veterinary Medicine, Uberlândia, Minas Gerais, Brazil.
- School of Veterinary Medicine, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil.
- Letur, Albacete, Spain. Electronic address: copicuervo@hotmail.com.
MeSH Terms
- Animals
- Embryo, Mammalian
- Endometrium
- Estrogens
- Estrus
- Female
- Horses
- Progesterone
Citations
This article has been cited 2 times.- Segabinazzi LGTM, Andrade LRP Jr, Alvarenga MA, Dell'Aqua JA Jr, Canisso IF. Use of Intravaginal Progesterone-Releasing Device Results in Similar Pregnancy Rates and Losses to Long-Acting Progesterone to Synchronize Acyclic Embryo Recipient Mares. Vet Sci 2021 Sep 10;8(9).
- Barbosa LA, Maran AP, de Almeida MER, Guimarães EC, Bringel B, Douglas RH, Lima TFG, da Silva ESM. Plasma Estradiol and Endometrial Edema Profile in Acyclic Mares After Single Administration of 17-β Estradiol, Estradiol Benzoate and Estradiol Cypionate. Reprod Domest Anim 2025 Aug;60(8):e70108.
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